Function:     errorf

Purpose:      error, using variable arguments

Category:     UTILITY, USER-INTERFACE

Author:       Do Kester

Use:  
void errorf( 
	int	error_level,	IN : errlev as in ERROR
	char	*fmt,		IN : fmt as in printf
	        ... )		IN : variable arguments as in printf

Description:
	The declaration of this function is in "userfio.h",
	where similar functions for anyoutf, statusf and userfxxx
	are declared too.
	This function uses an internal buffer of 80 characters long.

Comment:      This routine is NOT callable in FORTRAN.

Updates:      06 Aug 1991: DK, Creation date
              04 Jun 1992: DK, into the system.